Information on old American city (5)
I believe the answer is:
genoa
'city' is the definition.
(I know that Genoa is a city)
'information on old american' is the wordplay.
'information' becomes 'gen' (gen can informally mean information).
'on' is a charade indicator (letters next to each other).
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'american' becomes 'a' (common abbreviation - e.g. in organisation names).
'gen'+'o'+'a'='GENOA'
(Other definitions for genoa that I've seen before include "North Italian port" , "Italian city has no age, oddly" , "City of Italy" , "Type of rich fruit cake" , "NW Italian sea port" .)